What is a board foot?
Unlike square footage, which measures area, board footage measures volume. You use it when purchasing multiple boards of lumber in various sizes.
By definition, one board foot of lumber is one square foot that is one-inch thick. If you would like to convert regular volume units into board feet, use the following relation:
1 board foot = 144 cubic inches = 1/12 cubic foot
How to calculate board feet?
Surprisingly, the calculations are extremely easy! All you need to do is use the board foot formula below:
board feet = length (ft) × width (in) × thickness (in) / 12
Pay special attention to the units! The length of the wooden board should be expressed in feet, while the width and thickness – in inches.
Example
Calculating Board Feet
Board feet is a measurement used to determine the volume of lumber. The general formula to calculate board feet is:
\[ \text{Board Feet} = \frac{\text{Thickness (in inches)} \times \text{Width (in inches)} \times \text{Length (in feet)}}{12} \]Calculating the Board Feet of a Rectangular Board
If you have a rectangular board, you can calculate its board feet using its dimensions. The formula is:
\[ \text{Board Feet} = \frac{\text{Thickness} \times \text{Width} \times \text{Length}}{12} \]Example:
If a board has the following dimensions: Thickness = 2 inches, Width = 6 inches, and Length = 8 feet, the board feet can be calculated as follows:
- Step 1: Multiply the dimensions: \( 2 \times 6 \times 8 = 96 \)
- Step 2: Divide by 12 to get board feet: \( 96 \div 12 = 8 \) board feet.
Calculating the Total Board Feet for Multiple Boards
If you have multiple boards of the same dimensions, simply multiply the board feet of one board by the number of boards.
Example:
If you have 5 boards, each with Thickness = 2 inches, Width = 6 inches, and Length = 8 feet:
- Step 1: Calculate board feet for one board: \( 8 \) board feet.
- Step 2: Multiply by the number of boards: \( 8 \times 5 = 40 \) board feet.
Real-life Applications of Board Foot Calculation
Board foot calculation is widely used in various industries, such as:
- Estimating the total amount of lumber needed for construction and woodworking projects.
- Determining the cost of lumber purchases based on board feet pricing.
- Helping lumberyards and suppliers measure and price wood accurately.
Common Operations with Board Foot Calculation
Single Board: \( \text{Board Feet} = \frac{\text{Thickness} \times \text{Width} \times \text{Length}}{12} \)
Multiple Boards: \( \text{Total Board Feet} = \text{Board Feet per Board} \times \text{Number of Boards} \)
Irregular Lumber: Estimate average dimensions and apply the same formula to approximate board feet.
| Object Type | Description | Steps to Calculate Board Feet | Example |
|---|---|---|---|
| Single Board | Calculating the board feet of a single wooden board using its dimensions. |
|
If the board is 2 inches thick, 6 inches wide, and 8 feet long, the board feet calculation is \( \frac{2 \times 6 \times 8}{12} = 8 \) board feet. |
| Multiple Boards | Calculating the total board feet for multiple boards of the same dimensions. |
|
If you have 5 boards, each 2 inches thick, 6 inches wide, and 8 feet long, the total board feet is \( 8 \times 5 = 40 \) board feet. |
| Irregular Lumber | Finding the board feet for irregularly shaped lumber. |
|
If an irregular board has an average thickness of 1.5 inches, an average width of 7 inches, and a length of 10 feet, the board feet calculation is \( \frac{1.5 \times 7 \times 10}{12} = 8.75 \) board feet. |
| Real-life Applications | Using board foot calculations for construction, woodworking, and lumber purchasing. |
|
If a project requires 200 board feet and lumber costs $5 per board foot, the total cost is \( 200 \times 5 = 1000 \) dollars. |
